For some inexplicable reason, shares of the bankrupt investment bank, which trade on the loosely regulated over-the-counter Pink Sheets, changed hands some 73 million times on Friday. That’s a lot of trading in a stock that’s been worthless for nearly 12 months.

Indeed, on a typical day, the average trading volume in Lehman shares is about 2.6 million. The last time Lehman’s stock came anywhere close to today’s trading volume was way back in October, about a month after the Wall Street firm filed for bankruptcy.

Then again, today’s trading surge boosted Lehman’s closing stock price to 15 cents. It had been sitting around 5 cents for months. Better yet, Lehman now has a respectable market cap of $103 million–not too shabby for a small-cap company on the Pink Sheets.

Of course, this trading in Lehman is just crazy. There’s not good explanation for it. Just as there is no good explanation for the big surge in shares of American International Group.

Maybe this is just a case of traders trading trash financials to score a quick profit because they can’t find anything else to trade.